Controlling The Firing Time of Porcelain Enamel
At a certain firing temperature, the time required for the enamel product to be put from the furnace mouth of the box furnace to the firing is just taken out is called the firing time (in a continuous firing furnace with a heat exchange zone, because the product is entering the firing Part of the heat has been absorbed before the belt, and the burning time of the product in the box furnace should be referred to and converted into the linear speed of the continuous burning furnace. After a small batch of trial burning, the appropriate linear speed value should be summarized). In the firing process of the powder layer, whether the complex physical and chemical reactions are perfect or not depends on the firing temperature, and the firing time is also one of the basic conditions.
The firing temperature and time of enamel products can compensate each other to a certain extent, but it should be based on temperature and adjusted or compensated by time. In actual production, when the furnace temperature is close to the upper limit of the firing temperature, the time can be appropriately close to the lower limit of the firing time, but the wrong practice of fast enamelling of thin powder and fast firing at high temperature should be prevented.
In short, the relationship between the firing temperature and the time is based on the heat required for the enamel product. Generally, for large products, the iron billet is thicker, and the enameling powder layer is thicker, which requires more heat. Can adopt higher firing temperature and longer firing time. For small enamel products, the material used is thin, the enamel powder coating layer is relatively thin, and the amount of heat required is also less. Lower firing temperature and shorter firing time can be used.
The traditional low-temperature long-firing process of enamel refers to choosing close to the lower limit within the firing temperature range of the enamel frit, and close to the upper limit within the firing time range, which is beneficial to improve the quality of the enamel product.